asn1rt

ASN.1 runtime support functions

This module is the interface module for the ASN.1 runtime support functions.
To encode and decode ASN.1 types in runtime the functions in this module
should be used.

Functions

start() -> ok |{error,Reason}

Reason = term()

Starts the asn1 server that loads the drivers.

The server schedules a driver that is not blocked by
another caller. The driver is used by the asn1 application if
specs are compiled with options [per_bin, optimize] or
[ber_bin, optimize, driver]. The server will be started
automatically at encode/decode if it isn't done explicitly. If
encode/decode with driver is used in test or industrial code
it is a performance gain to start it explicitly to avoid the
one time load in run-time.

decode(Module,Type,Bytes) -> {ok,Value}|{error,Reason}

Decodes Type from Module from the list of bytes or
binary Bytes. If the module is compiled with ber_bin
or per_bin option Bytes must be a binary.
Returns {ok,Value} if successful.

encode(Module,Type,Value)-> {ok,BinOrList} | {error,Reason}

Module = Type = atom()

Value = term()

BinOrList = Bytes | binary()

Bytes = [Int|binary|Bytes] when integer(Int), Int >= 0, Int =< 255

Reason = term()

Encodes Value of Type defined in the ASN.1 module
Module. Returns a possibly nested list of bytes and or binaries
if successful. If Module was compiled with the options per_bin and optimize the result is a binary. To get as
fast execution as possible the
encode function only performs rudimentary tests that the input
Value
is a correct instance of Type. The length of strings is for example
not always checked.

info(Module) -> {ok,Info} | {error,Reason}

Module = atom()

Info = list()

Reason = term()

info/1 returns the version of the asn1 compiler that was
used to compile the module. It also returns the compiler options
that was used.

load_driver() -> ok | {error,Reason}

Reason = term()

This function loads the linked-in driver before the first call
to encode. If this function is not called the driver will be loaded
automatically at the first call to encode. If one doesn't want the
performance cost of a driver load when the application is running,
this function makes it possible to load the driver in an
initialization.

The driver is only used when encoding/decoding ASN.1 files that
were compiled with the options per_bin and optimize.

unload_driver() -> ok | {error,Reason}

Reason = term()

This function unloads the linked-in driver.
When the driver has been loaded it remains in the environment until
it is unloaded. Normally the driver should remain loaded, it is
crucial for the performance of ASN.1 encoding.

The driver is only used when ASN.1 modules have been compiled
with the flags per_bin and optimize.

utf8_binary_to_list(UTF8Binary) -> {ok,UnicodeList} | {error,Reason}

UTF8Binary = binary()

UnicodeList = [integer()]

Reason = term()

utf8_binary_to_list/1 Transforms a UTF8 encoded binary
to a list of integers, where each integer represents one
character as its unicode value. The function fails if the binary
is not a properly encoded UTF8 string.

utf8_list_to_binary(UnicodeList) -> {ok,UTF8Binary} | {error,Reason}

UnicodeList = [integer()]

UTF8Binary = binary()

Reason = term()

utf8_list_to_binary/1 Transforms a list of integers,
where each integer represents one character as its unicode
value, to a UTF8 encoded binary.

validate(Module,Type,Value) -> ok | {error,Reason}

Module = Type = atom()

Value = term()

Validates that Value conforms to Type
from Module. Not implemented in this version of the ASN.1 application.